As the ketogenic diet uses lipids rather than carbohydrates as the primary energy source, it is essential that children are screened for disorders of fat metabolism, to avoid a metabolic crisis.1   

The absolute and relative contraindications and other pre-existing complications are listed below.

Absolute contraindications:

  • Carnitine deficiency (primary)
  • Carnitine palmitoyltransferase (CPT I or II) deficiency
  • Carnitine translocase deficiency
  • β-oxidation defects
  • Medium-chain acyl dehydrogenase deficiency (MCAD)
  • Long-chain acyl dehydrogenase deficiency (LCAD)
  • Short-chain acyl dehydrogenase deficiency (SCAD)
  • Long-chain 3-hydroxyacyl-CoA deficiency
  • Medium-chain 3-hydroxyacyl-CoA deficiency.
  • Pyruvate carboxylase deficiency
  • Porphyria

Most of these conditions can be excluded on a routine urine metabolic screen and blood carnitine profile.

Relative contraindications:

  • Inability to maintain adequate nutrition
  • Surgical focus identified by neuroimaging and video EEG monitoring
  • Parent or caregiver hesitance re: fussy eating and potential non-compliance with diet
  • Bulbar dysfunction or Gastroesophageal disease -> aspiration risk

Most patients will require a risk assessment of aspiration as fat-aspiration can lead to severe complications, such as fat-aspiration pneumonia, and can be lethal.

Other pre-existing complicating factors to be considered:

  • Presence of kidney stones
  • Dyslipidaemia
  • Liver disease
  • Failure to thrive
  • Gastroesophageal reflux
  • Poor oral intake
  • Constipation
  • Cardiomyopathy
  • Chronic metabolic acidosis
  • High carbohydrate content of current medications
  • 1Kossoff et al. (2018). Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group. Epilepsia Open, 3(2):175–192.